<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script>
			
			let num1 = + prompt('请输入第一个数：',0);
			let num2 = + prompt('请输入第二个数：',0);
			let num3 = + prompt('请输入第三个数：',0);
			
			//定义一个变量记录最大数
			let max = num1;
			
			if(num2 > max){
				max = num2;
			}
			
			if(num3 > max){
				max = num3;
			}
			
			console.log(max);
		</script>
	</body>
</html>